LED Current Draw?

Simple question for you guys. I am trying to drive an LED with a 5V power source and a resistor in series.

I understand how to calculate the minimum resistance needed to drive the LED with maximum current ((voltage supply - forward voltage) / maximum current) but I can't for the life of me figure out how to calculate the current through an LED with a given resistor.

Say, we have our 5V source --> 330 ohm resistor --> LED with forward voltage of 3.15V --> ground. What's the current flowing through the circuit?

With this, you can apply Ohm's Law to calculate the current through the resistor (you know the voltage across it and the resistance). Since it is a series circuit, the current through the resistor = the current through the LED.

With this, you can apply Ohm's Law to calculate the current through the resistor (you know the voltage across it and the resistance). Since it is a series circuit, the current through the resistor = the current through the LED.

Click to expand...

Ugh, of course. Too simple. I knew I had enough information to back that number out, I suppose it has just been a long day and my brain already went into weekend mode. Thanks!